uva 10917

来源：互联网发布：linux apache启动命令编辑：程序博客网时间：2024/06/05 20:00

这是我在一以前写的SPFA上加了一个记忆话搜索救过了，直接上代码吧……

#include <iostream>#include <cstdio>#include <vector>#include <queue>#include <stdlib.h>#include <memory.h>#define maxn 1005#define INF 1<<29using namespace std;int max(int a,int b){return a>b?a:b;}int M,N,X;struct farm{    int next,weight;}tmp,tmp2;vector<farm>Grap[maxn];bool flag[maxn];int dist[maxn];bool cango[maxn][maxn];int map[maxn][maxn];int dp[maxn];void SPFA(int v0){    memset(flag,0,sizeof flag);    dist[v0]=0;    queue<int>Q;    Q.push(v0);    flag[v0]=1;    while(!Q.empty())    {        int temp=Q.front();        Q.pop();        flag[temp]=0;        int END=Grap[temp].size();        for(int i=0;i<END;i++)        {            tmp=Grap[temp][i];            if(dist[temp]<INF&&dist[temp]+tmp.weight<dist[tmp.next])            {                dist[tmp.next]=dist[temp]+tmp.weight;                if(!flag[tmp.next])                {                    Q.push(tmp.next);                    flag[tmp.next]=1;                }            }        }    }}int dfs(int cur){    if(dp[cur]!=-1)return dp[cur];    int temp=0;    for(int i=1;i<=N;i++)    if(cango[cur][i])temp+=dfs(i);    return dp[cur]=temp;}int main(){//    freopen("in.txt","r",stdin);    int u,v,w;    while(~scanf("%d",&N)&&N)    {        scanf("%d",&M);        memset(dist,0x3f,sizeof dist);        memset(map,0x3f,sizeof map);        memset(cango,0,sizeof cango);        memset(dp,-1,sizeof dp);        for(int i=1;i<=M;i++)        {            scanf("%d%d%d",&u,&v,&w);            tmp.next=v,tmp.weight=w;            tmp2.next=u,tmp2.weight=w;            Grap[v].push_back(tmp2);            Grap[u].push_back(tmp);            map[u][v]=map[v][u]=w;        }        SPFA(2);        for(int i=1;i<=N;i++)        for(int j=1;j<=N;j++)        if(dist[i]>dist[j]&&map[i][j]<1061109567)cango[i][j]=1;        dp[2]=1;        dfs(1);        printf("%d\n",dp[1]);    }    return 0;}

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